The present invention relates to a clutch type switch for a chainsaw to prevent the chainsaw from being activated by touching the trigger unintentionally.
A conventional switch device for a power tool generally includes a trigger which is engaged with a trigger assembly. When pulling the trigger, the circuit of the power tool is activated and the tool is operated. However, most of the triggers have no safety device to avoid the user to touch the trigger unintentionally so that it is possible that the trigger is pulled unintentionally and the chainsaw for example is running. This is extremely dangerous so that there is a need to develop a safety device to prevent the situation from happening.
In accordance with one aspect of the present invention, there is provided a clutch safety switch for a power tool and the clutch safety switch comprises a casing having a slot for a safety member slidably engaged therewith. A lug extends from an underside of the safety member and a trigger is pivotally located in the casing and has a protrusion which is interfered by the lug of the safety member. A link has an end thereof connected to the safety member. A gear is received in the casing and connected to a power source. The gear is independently mounted to an output shaft and a plurality of engaging recesses are defined in the gear. A plurality of guide rods and guide members respectively extend from an inside of the casing. A clutch member is mounted to the output shaft and has a plurality of blades each of which has a guide slot in which respective one of a plurality of guide rods extends. Each blade has a tapered extension extending therefrom which is able to be movable along the guide member. An engaging member is movably mounted to the output shaft and has bosses extending from a side thereof. A cover is fixed on the clutch member end the engaging member is retained in a central hole in the clutch member by the cover. A link is connected between the safety member and one of the blades of the clutch member.
The primary object of the present invention is to provide a clutch safety switch for a power tool wherein the trigger cannot be squeezed if the safety member is not slid. The power is not transferred to the chainsaw when releasing the trigger.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.